BUFFALO — Tri-City School District officials said Wednesday that they believe various mold problems that have plagued the district since last fall are finally behind them.

School officials had to push back the start of school for prekindergarten students until Sept. 2 after two rooms in the 2001 addition to the school tested positive for mold days before the start of the year.

School board president Bill Marvin said Wednesday that the mold was caused by a “design flaw” in the chiller system that finally manifested itself.

When environmental engineers were called in to investigate, they found that the cooling system installed in 2001 was three times too big and that the contractor used rubber instead of fiberglass insulation, he said.

Over the years, the rubber insulation deteriorated, the pipes became exposed and condensation built up, which spawned mold growth, he said. To make things worse, Marvin added, engineers discovered a leaky pipe.

He said the district looked into legal action against the contractor but was told it didn’t have a case.

“Our counsel advised it would be a fruitless enterprise to pursue legal remediation,” Marvin said. “It all leaves a bad taste in your mouth when you find out that this was the thing causing the whole issue.”

Since the discovery, crews hired by the district have been hard at work cleaning rooms, testing for mold and replacing drywall the past two weeks, School Superintendent Jill Larson said.

Larson, who’s in her first year as Tri-City superintendent, said everything is on schedule for prekindergarten students to start school next week. And to avoid having the problem reoccur, she said, window air-conditioning units will be used to cool that part of the building rather than the old chiller system.

“They know they’re on a deadline,” she said.

The discovery of mold in the prekindergarten addition came around the same time the district was moving on from problems it faced with mold last year.

Larson said the district recently received good news that the locker rooms in the basement were mold-free.

Ray Hughes, facilities liaison, said the mold in the basement last year was caused by water backing up and poor ventilation. The district has since cleaned the basement and modified the way the room is vented and water drains, he said.

Furthermore, the district had to have all of its heating ventilators professionally cleaned last year because they had become a growth point for mold. As a result, classes were canceled for two days because the district couldn’t heat the building that houses students in kindergarten through high school.

The whole process has been an expensive endeavor.

Larson said the bill so far probably totals $250,000 — not including the latest work being done at the prekindergarten addition.

Page 2 of 2 - Hughes estimated the latest project would add another $50,000 to the total, although he said that’s a guess because the project didn’t go through the normal bidding process due to the urgency.

Marvin said mold remediation has forced the district to delay other projects, most notably replacing a leaky roof.

However, school officials say cost hasn’t been and won’t be a deterring factor when it comes to ensuring the building is mold-free.

“Student safety is our top priority,” Larson said. “We’re going to stay on top of it.”